code: def test_overlay(self):
      NdOverlay(list(enumerate([self.view1, self.view2, self.view3])))
  
file_path: holoviews/holoviews/tests/core/test_layers.py
imports: import unittest
  import numpy
  from holoviews import Element, NdOverlay
label_desc: Use image node_id 1 for calling the OverlayTest obj's underlying member method code with example usage: obj.test_overlay() without return types